======================================
| [821.065425][T10876] #0: ffffffff8abe7a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink (net/core/rtnetlink.c:3512)
| [821.065733][T10876] #1: ffffffff8abd6630 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  821.066067][T10876]
| [  821.066067][T10876] stack backtrace:
[  821.066529][T10876] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  821.066766][T10876] Call Trace:
[  821.066962][T10876]  <TASK>
[821.067090][T10876] dump_stack_lvl (lib/dump_stack.c:123)
[821.067349][T10876] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[821.067604][T10876] validate_chain (kernel/locking/lockdep.c:3894)
[821.067852][T10876] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[821.068113][T10876] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228)
[821.068328][T10876] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[821.068453][T10876] __lock_acquire (kernel/locking/lockdep.c:5226)
[821.068619][T10876] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[821.068793][T10876] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[821.068999][T10876] ? netconsole_process_cleanups_core (drivers/net/netconsole.c:242 (discriminator 11))
[821.069209][T10876] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[821.069377][T10876] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[821.069544][T10876] ? lock_acquire (kernel/locking/lockdep.c:5822)
[821.069722][T10876] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[821.069934][T10876] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[821.070067][T10876] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[821.070277][T10876] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[821.070453][T10876] ? __lock_release (kernel/locking/lockdep.c:5525)
[821.070607][T10876] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[821.070768][T10876] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[821.070915][T10876] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[821.071067][T10876] __netdev_upper_dev_unlink (net/core/dev.c:8000 (discriminator 11) net/core/dev.c:8017 (discriminator 11) net/core/dev.c:8167 (discriminator 11))
[821.071239][T10876] ? __pfx___netdev_upper_dev_unlink (net/core/dev.c:8151)
[821.071442][T10876] ? __mutex_unlock_slowpath (./arch/x86/include/asm/atomic64_64.h:101 ./include/linux/atomic/atomic-arch-fallback.h:4329 ./include/linux/atomic/atomic-long.h:1506 ./include/linux/atomic/atomic-instrumented.h:4481 kernel/locking/mutex.c:913)
[821.071615][T10876] ? __pfx___mutex_unlock_slowpath (kernel/locking/mutex.c:890)
[821.071822][T10876] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[821.071988][T10876] netdev_upper_dev_unlink (net/core/dev.c:8190)
[821.072149][T10876] ? __pfx_netdev_upper_dev_unlink (net/core/dev.c:8190)
[821.072348][T10876] ? netconsole_netdev_event (drivers/net/netconsole.c:1082)
[821.072508][T10876] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3189 kernel/locking/mutex.h:47 kernel/locking/mutex.c:66)
[821.072656][T10876] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[821.072820][T10876] ? netdev_master_upper_dev_get (net/core/dev.c:7230)
[821.073005][T10876] vrf_device_event (drivers/net/vrf.c:1110 drivers/net/vrf.c:1119 drivers/net/vrf.c:1804) vrf
[821.073157][T10876] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[821.073309][T10876] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[821.073457][T10876] unregister_netdevice_many_notify (net/core/dev.c:11571)
[821.073641][T10876] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228)
[821.073801][T10876] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[821.073918][T10876] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[821.074098][T10876] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[821.074283][T10876] ? kfree (mm/slub.c:4613 mm/slub.c:4761)
[821.074398][T10876] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[821.074546][T10876] ? vlan_vid_del (net/8021q/vlan_core.c:368 net/8021q/vlan_core.c:387)
[821.074702][T10876] rtnl_dellink (net/core/rtnetlink.c:3478 net/core/rtnetlink.c:3518)
[821.074851][T10876] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[821.075016][T10876] ? find_held_lock (kernel/locking/lockdep.c:5339)
[821.075164][T10876] ? __lock_release (kernel/locking/lockdep.c:5525)
[821.075311][T10876] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[821.075457][T10876] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[821.075604][T10876] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[821.075779][T10876] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6900)
[821.075926][T10876] ? __pfx_rtnl_dellink (net/core/rtnetlink.c:3484)
[821.076082][T10876] rtnetlink_rcv_msg (net/core/rtnetlink.c:6902)
[821.076229][T10876] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[821.076381][T10876] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228)
[821.076530][T10876] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[821.076641][T10876] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[821.076800][T10876] netlink_rcv_skb (net/netlink/af_netlink.c:2543)
[821.076946][T10876] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6805)
[821.077091][T10876] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2520)
[821.077248][T10876] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340)
[821.077406][T10876] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333)
[821.077552][T10876] netlink_unicast (net/netlink/af_netlink.c:1322 net/netlink/af_netlink.c:1348)
[821.077713][T10876] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1333)
[821.077859][T10876] ? find_held_lock (kernel/locking/lockdep.c:5339)
[821.078008][T10876] netlink_sendmsg (net/netlink/af_netlink.c:1892)
[821.078153][T10876] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1811)
[821.078329][T10876] ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2594)
[821.078490][T10876] ? __pfx_____sys_sendmsg (net/socket.c:2540)
[821.078652][T10876] ? __pfx_copy_msghdr_from_user (net/socket.c:2520)
[821.078851][T10876] ___sys_sendmsg (net/socket.c:2650)
[821.079000][T10876] ? __pfx____sys_sendmsg (net/socket.c:2637)
[821.079147][T10876] ? kasan_save_stack (mm/kasan/common.c:49)
[821.079297][T10876] ? kasan_save_stack (mm/kasan/common.c:48)
[821.079465][T10876] ? __kasan_record_aux_stack (mm/kasan/generic.c:544)
[821.079628][T10876] ? __call_rcu_common.constprop.0 (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:123 kernel/rcu/tree.c:3087)
[821.079845][T10876] ? __x64_sys_close (fs/open.c:1557 fs/open.c:1539 fs/open.c:1539)
[821.080008][T10876] ? do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[821.080168][T10876] ? entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[821.080371][T10876] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[821.080532][T10876] ? find_held_lock (kernel/locking/lockdep.c:5339)
[821.080702][T10876] ? __lock_release (kernel/locking/lockdep.c:5525)
[821.080860][T10876] ? __virt_addr_valid (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:962 ./include/linux/mmzone.h:2058 arch/x86/mm/physaddr.c:65)
[821.081024][T10876] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[821.081193][T10876] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[821.081429][T10876] __sys_sendmsg (net/socket.c:2680)
[821.081681][T10876] ? __pfx___sys_sendmsg (net/socket.c:2665)
[821.081926][T10876] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[821.082246][T10876] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[821.082485][T10876] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  821.082789][T10876] RIP: 0033:0x7f696771f9a7
[ 821.083054][T10876] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[  821.083917][T10876] RSP: 002b:00007ffc652a7618 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  821.084315][T10876] RAX: ffffffffffffffda RBX: 00007ffc652a7d40 RCX: 00007f696771f9a7
[  821.084666][T10876] RDX: 0000000000000000 RSI: 00007ffc652a7680 RDI: 0000000000000005
[  821.085068][T10876] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[  821.085451][T10876] R10: 00007f69675ddef8 R11: 0000000000000246 R12: 0000000000000002


Finger prints:
print_deadlock_bug:validate_chain:__lock_acquire:down_read:blocking_notifier_call_chain